{"title":"Age Distribution of Red Tree Voles in Northern Spotted Owl Pellets Estimated from Molar Tooth Development","authors":"C. Marks-Fife, E. Forsman, Katie M. Dugger","doi":"10.3955/046.093.0304","DOIUrl":"https://doi.org/10.3955/046.093.0304","url":null,"abstract":"Abstract We used molar measurements from 136 known-age red tree voles (Arborimus longicaudus) to develop regression models that could estimate tree vole age from skeletonized remains. The best regression included a quadratic structure of the ratio between two measurements, crown height and anterior height, and natural log-transformed age in days. The regression predicted that molar roots begin to develop at 40 days of age and that molar crowns are worn completely away at 1,177 days of age. We used the regression to estimate the age distribution of 1,703 red tree voles found in northern spotted owl (Strix occidentalis caurina) pellets collected in western Oregon during 1970–2009. The age distribution of red tree voles in pellets was dominated by young individuals, with 81% younger than one year and only 0.5% older than two years. The proportion of individuals 61–120 days old was particularly high relative to other age classes. The proportion of subadult (52–120 days old) individuals exhibited regional variation between the Oregon Cascades and the Coast Range. Localized annual variation in age distribution was low, exhibited no evidence of cyclic variation, and was positively associated with local precipitation rates during the spotted owl nesting season (March–June). We hypothesize that the age distribution of tree voles in owl pellets may be similar to the age structure of tree vole populations in the wild, but acknowledge that this is virtually impossible to test because tree voles cannot be adequately sampled using conventional small mammal capture methods.","PeriodicalId":49743,"journal":{"name":"Northwest Science","volume":"93 1","pages":"193 - 208"},"PeriodicalIF":0.4,"publicationDate":"2020-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42632140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Simple Guidelines to Prepare Forests for Global Change: The Dog and the Frisbee","authors":"K. Puettmann, C. Messier","doi":"10.3955/046.093.0305","DOIUrl":"https://doi.org/10.3955/046.093.0305","url":null,"abstract":"Abstract Most suggestions for adapting forest management in times of rapid global change have focused on tree regeneration, mortality, and productivity under predicted future climates. Adaptation to other aspects of global change, such as invasive species or changes in social settings, has received much less attention, which may be partially due to the high unpredictability of such events. Based on a review of recent silvicultural practices and ecological theory with a special emphasis on complex adaptive systems, we propose three guidelines for increasing the likelihood that forests will provide desired levels of a variety of ecosystem services in an increasingly variable and uncertain future. Basically, the guidelines promote a system level instead of the traditional command and control approach (sensu Holling and Meffe 1996) to silviculture. They are based on the well-supported ecological notions that having a high diversity and redundancy of key elements that are well connected across spatial, temporal, and organizational scales will allow forests to adapt on their own in response to predictable and unpredictable perturbations without the need for major management interventions. The guidelines encourage the maintenance of stand structural and compositional diversity at multiple spatial and temporal scales, thus reinforcing cross-hierarchical interactions in ecosystems, with an emphasis on encouraging self-organization. We provide examples of silvicultural practices as they relate to these guidelines.","PeriodicalId":49743,"journal":{"name":"Northwest Science","volume":"93 1","pages":"209 - 225"},"PeriodicalIF":0.4,"publicationDate":"2020-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47464839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amy D. Lockner, S. Cook, Mark J. Kimsey, A. McDonald, T. Shaw
{"title":"Toxicity to Douglas-Fir Tussock Moth and Foliar Concentration of Individual Monoterpenes in Douglas-Fir Following Fertilization in Thinned Stands","authors":"Amy D. Lockner, S. Cook, Mark J. Kimsey, A. McDonald, T. Shaw","doi":"10.3955/046.093.0301","DOIUrl":"https://doi.org/10.3955/046.093.0301","url":null,"abstract":"Abstract Tree susceptibility and suitability for herbivorous insects depends upon a wide array of chemical compounds including potential toxins such as monoterpenes. Silvicultural techniques such as thinning and fertilization may change the concentration of these compounds within tree tissue foliage. The relative toxicities to Douglas-fir tussock moth larvae of five monoterpenes commonly present in host foliage were determined in laboratory assays. Of the five monoterpenes tested, limonene and γ-terpinene were significantly more toxic to the larvae then β-pinene, 3-carene or α-pinene. We also examined the effect of three fertilization treatments applied to previously thinned stands on the concentration of foliar monoterpenes one year following stand thinning. No significant differences were detected among treatments in the concentration of individual or total monoterpenes present in foliage. The effect of stand thinning may have overwhelmed any short-term fertilization impacts.","PeriodicalId":49743,"journal":{"name":"Northwest Science","volume":"93 1","pages":"163 - 170"},"PeriodicalIF":0.4,"publicationDate":"2020-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49339185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mehmet A. Balkan, Nathan U. Stewart, Emily S. Kauffman, Emily R. Wolfe, D. Ballhorn
{"title":"Genotypic Diversity and Host-Specificity of Frankia Bacteria Associated with Sympatric Populations of Alnus rubra and Alnus rhombifolia in Oregon","authors":"Mehmet A. Balkan, Nathan U. Stewart, Emily S. Kauffman, Emily R. Wolfe, D. Ballhorn","doi":"10.3955/046.093.0307","DOIUrl":"https://doi.org/10.3955/046.093.0307","url":null,"abstract":"Abstract Biological nitrogen fixation is one of the most critical processes contributing to ecosystem productivity and stability on a global scale. In temperate climates of the northern hemisphere, plant-root associated bacteria of the genus Frankia are the major nitrogen fixers in forest environments. Trees belonging to the genus Alnus are the most widespread hosts of Frankia in the Pacific Northwest, and a myriad of biotic and abiotic factors can influence the robustness of this symbiosis. Host identity and bacterial strain are important features that can impact Alnus-Frankia association, but little is known about the interplay of intrageneric hosts that co-occur in natural settings. In this study we investigated the genetic diversity and host specificity of Frankia bacteria associated with sympatrically occurring populations of Alnus rubra (red alder) and Alnus rhombifolia (white alder) in Oregon. Based on sequence analysis of the nifH gene recovered from root nodules we found low overall bacterial diversity. One dominant Frankia genotype was associated with both host species, indicating a lack of strong host specificity in this system. Our results suggest that certain intrageneric plant hosts with overlapping distributions show cross-compatibility with symbiotic actinorhizal bacteria, and that low strain diversity of these bacteria can persist across mixed host populations.","PeriodicalId":49743,"journal":{"name":"Northwest Science","volume":"93 1","pages":"244 - 252"},"PeriodicalIF":0.4,"publicationDate":"2020-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44834757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rita K. McCreesh, K. Fox-Dobbs, P. Wimberger, Kent Woodruff, G. Holtgrieve, Thomas Pool
{"title":"Reintroduced Beavers Rapidly Influence the Storage and Biogeochemistry of Sediments in Headwater Streams (Methow River, Washington)","authors":"Rita K. McCreesh, K. Fox-Dobbs, P. Wimberger, Kent Woodruff, G. Holtgrieve, Thomas Pool","doi":"10.3955/046.093.0203","DOIUrl":"https://doi.org/10.3955/046.093.0203","url":null,"abstract":"Abstract North American beavers (Castor canadensis) were targeted within North American headwater landscapes by European loggers and fur traders in the 19th century, reducing beaver populations to near extinction by 1900. The extirpation of beavers from river networks has had profound effects on riparian zones, including channel geomorphology, temperature regimes, sediment storage, channel-floodplain connectivity, carbon storage and nutrient dynamics. Consequently, reintroducing beavers has been provisionally implemented as a restoration approach within some watersheds. We characterized how reintroduced beavers influence the short-term dynamics of organic material accumulation within the sediments of 1st and 2nd order streams within the Methow River watershed of Washington State. In collaboration with the Methow Beaver Project, we identified four creeks where they had reintroduced beavers within the past five years, as well as a control non-beaver pond. At each site, we collected shallow sediment cores from upstream, downstream, and within beaver ponds, and then measured organic material via elemental analyses of sediment carbon (%C) and nitrogen (%N) content. We compared those samples to sediments accumulated in local pond areas not created by beaver activity. Our results show greater organic C and N content of sediments in beaver ponds than non-beaver ponds. C/N ratios indicate elevated accumulation of allochthonous organic material in beaver impoundment sediments that would otherwise not be integrated into headwater streams from the terrestrial landscape. These findings suggest that the reintroduction of beavers could be an effective means to promote restoration of whole ecosystem function.","PeriodicalId":49743,"journal":{"name":"Northwest Science","volume":"93 1","pages":"112 - 121"},"PeriodicalIF":0.4,"publicationDate":"2019-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41372114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Katie M. Moriarty, K. Aubry, Connor N. Morozumi, B. L. Howell, P. J. Happe, K. Jenkins, K. Pilgrim, M. Schwartz
{"title":"Status of Pacific Martens (Martes caurina) on the Olympic Peninsula, Washington","authors":"Katie M. Moriarty, K. Aubry, Connor N. Morozumi, B. L. Howell, P. J. Happe, K. Jenkins, K. Pilgrim, M. Schwartz","doi":"10.3955/046.093.0204","DOIUrl":"https://doi.org/10.3955/046.093.0204","url":null,"abstract":"Abstract Pacific martens (Martes caurina) remain common in montane regions of the Pacific states, yet their distribution and status on the Olympic Peninsula, Washington, is uncertain. Between 1968–2008, six reliable marten detections exist; a dead juvenile female (2008) indicates martens were reproducing on the Peninsula within the last decade. To assess the status of martens, we describe carnivore surveys conducted from 1991–2008 (n = 223 stations). Additionally, we present results from three survey efforts we conducted from 2013–2016 (n = 747 stations). Although a suite of carnivore species was detected, surveys from 1991–2008 failed to detect either martens or fishers. Surveys from 2013–2016 detected reintroduced fishers, and resulted in two marten detections near Mt. Olympus, 4 km apart. A marten was photographed opportunistically near Mt. Cruiser in 2015, 44 km from Mt. Olympus. Altogether, nine reliable detections of Pacific martens were obtained between 1968 and 2016, including three since 2008. Evidence suggests martens are absent from the lower elevation regions they once occupied and occur at exceedingly low densities at higher elevations. To understand the trend in marten populations on the Peninsula and develop appropriate conservation strategies, additional broad- and fine-scale surveys using detection devices that enable the genetic identification of individuals will be needed.","PeriodicalId":49743,"journal":{"name":"Northwest Science","volume":"93 1","pages":"122 - 136"},"PeriodicalIF":0.4,"publicationDate":"2019-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45348941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Coded-Wire Tag Sampling: The Case for Electronic-Field Detection","authors":"M. Masuda, A. Celewycz","doi":"10.3955/046.093.0202","DOIUrl":"https://doi.org/10.3955/046.093.0202","url":null,"abstract":"Abstract A clipped adipose fin served as an effective external mark indicating presence of a coded-wire tag (CWT) in salmon (Oncorhynchus spp.) from the 1960s until the mid 1990s when hatcheries in the Pacific Northwest began mass marking released fish with an adipose fin clip, but not necessarily a CWT. Since then, many CWT sampling programs of commercial fisheries have transitioned to electronic-field detection, while others are still visual-field only, examining snouts from all adipose-clipped salmon, even those without CWTs. Because some CWT salmon are released from hatcheries without any external marks, visual-field only programs also fail to sample these CWTs. In 2012, we used electronic tag detection at a processing plant in Kodiak, Alaska, to scan 1,201 Chinook salmon (O. tschawytscha) caught as bycatch in the US North Pacific groundfish fisheries in the Gulf of Alaska (GOA). Chinook salmon bycatch were also electronically scanned in partnerships with private industry: 3,713 salmon in the 2013–2016 US rockfish fishery in the central GOA, and 611 salmon in testing of salmon excluder devices in 2013 in the central GOA groundfish fisheries. Electronic-field detection increased CWT recovery rates by 20–24% over visual-field detection of adipose-clipped Chinook salmon, and an estimated 64–74% of adipose-clipped Chinook salmon sampled had no CWTs. Visual-field only CWT sampling programs may unnecessarily process large numbers of untagged, adipose-clipped salmon while also recovering fewer CWTs than comparable electronic sampling programs.","PeriodicalId":49743,"journal":{"name":"Northwest Science","volume":"93 1","pages":"102 - 111"},"PeriodicalIF":0.4,"publicationDate":"2019-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41779184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Phenotypic Differences in Open-Grown and Sheltered Cantharellus formosus","authors":"Daniel Zayonc, Tobis Z. Agrell","doi":"10.3955/046.093.0201","DOIUrl":"https://doi.org/10.3955/046.093.0201","url":null,"abstract":"Abstract Successful spore dispersal is a crucial part of the fungi life cycle, and many species achieve this using sporocarps which extend above the forest floor. The shape of sporocarps is known to affect dispersal success, but the local abiotic factors driving their morphology is understudied. In this study we examined the plasticity of sporocarp morphology and its effects on spore dispersal in the Pacific golden chanterelle (Cantharellus formosus). C. formosus that developed in sheltered microhabitats (n = 79), were measured to have significantly taller (P = 0.01) stipes and larger caps (P < 0.01) for a given stipe width compared to those developing in open microhabitats (n = 97). We were unable to detect increased dispersal success of C. formosus in field (n = 10). Longer stipes and larger caps are associated with increased dispersal abilities, while increased stipe thickness is connected to better stability. We suggest that sheltered C. formosus may grow into the open headspace, thus facilitating more effective spore dispersal. C. formosus growing in the open forest floor do not exhibit impeded dispersal and are thus shorter and smaller. Taken together, it is unlikely that there is a trade-off between morphologies that improve long distance dispersal or sporocarp stability.","PeriodicalId":49743,"journal":{"name":"Northwest Science","volume":"93 1","pages":"101 - 94"},"PeriodicalIF":0.4,"publicationDate":"2019-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47847520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Foliage Arthropod Biomass Equations for Open Vegetation Conditions of the Pacific Coast Range","authors":"C. Loehle, Melissa A. Scherr, Jake Verschuyl","doi":"10.3955/046.093.0206","DOIUrl":"https://doi.org/10.3955/046.093.0206","url":null,"abstract":"Abstract Field studies of arthropod abundance may also need to know biomass. Biomass is used in studies of food web structure and tropic cascades, and for estimating vertebrate food sources and plant damage from herbivory. Weighing individual insects is time-consuming and body length is a more practical field measurement. We develop an allometric equation for arthropod biomass (wet and dry weight) as a function of length for application to field studies in the Pacific Coast region, USA. Our results are consistent with prior all-taxa equations.","PeriodicalId":49743,"journal":{"name":"Northwest Science","volume":"93 1","pages":"155 - 158"},"PeriodicalIF":0.4,"publicationDate":"2019-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47973666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}